1. Field of the Invention
The present invention relates to a printing apparatus for ejecting ink on a printing medium from a print head supplied with ink through a tapered ink supply needle, and more particularly to an ink cartridge and an ink supply system removably attached to the printing apparatus.
2. Description of the Related Art
Typically, an ink cartridge having a supply port for providing ink is connected to a print head of a printing apparatus for ejecting ink on a printing medium from nozzle aperture of the print head. The printing apparatus has a hollow ink supply needle in the ink supply channel to supply ink to the print head. When the ink cartridge is mounted on the printing apparatus, the hollow ink supply needle is inserted into the ink supply port of the ink cartridge so that ink is introduced to the print head.
When the ink cartridge includes a porous member within its ink chamber for absorbing ink, the ink chamber receives a negative pressure by the porous member. Therefore, the ink cartridge needs to be sealed so as not to suck air or bubbles in the ink chamber, which would be undesirable.
FIG. 27 is a cross sectional view of an example of an ink artridge and an ink supply channel. The ink cartridge 112 has an ink supply port 114 and a packing member 120 contained in the ink supply port 114 and fitting with an ink supply needle 118 which is connected to a print head 116. The ink supply port 114 is sealed with a sealing film, not shown in the drawings, prior to use. When the ink supply needle 118 is inserted in the ink supply port 114 and fitted in the packing member 120, the ink supply needle 118 penetrates the sealing film. Ink is then provided to the print head 116 via the ink supply needle 118. The ink cartridge 112 is sealed by fitting the ink supply needle 118 with the packing member 120.
When the ink cartridge 112 is removed from the printing apparatus with ink left therein, the sealing of the ink supply needle 118 with the packing member 120 is released. The result is that ink leaks from the ink supply port 114 or that air or a bubble enters the ink supply port 114. This means that a user of the ink cartridge cannot remove the ink cartridge until ink in the ink cartridge is completely used up. The user cannot repeatedly exchange a plurality of ink cartridges with his choice while ink still remains in the ink cartridge. There has been provided an ink cartridge as disclosed, for example, in U.S. Pat. No. 5,777,646, having an elastic slit wall formed at an opening of an ink supply port and a ball slidably received in the ink supply port which is always urged against the elastic slit wall by a spring.
An ink supply channel of the conventional ink cartridge described above is opened by urging the ball with a hollow ink supply needle of the printing apparatus when the ink cartridge is mounted on the apparatus. The ink supply channel of the ink cartridge is closed when the hollow ink supply needle is removed from elastic slit wall because of the elastic force of the spring which always urges the ball against the elastic slit wall of the ink supply port. Therefore, ink does not leak from the ink supply port and air or bubble does not enter the ink supply port.
The conventional ink cartridge, however, has a drawback that the structure of the ink supply port is complicated as shown in FIG. 27. Therefore, the workability of the ink cartridge is deteriorated, and the manufacturing cost would rise up.
FIG. 28 shows another example of a conventional ink cartridge disclosed in Japanese patent application No. 5-229137 employing a packing member, or a rubber member disposed in the ink supply port and a ball which is urged against the packing member by a spring. Ink is supplied from an ink chamber to a print head via a cylindrical connecting means. The ball is urged by the cylindrical connecting means to move away from the packing member against the elastic force of the spring.
The ink cartridge illustrated in FIG. 28 has a packing member 134 disposed in the ink supply port 132 and a ball 136 abutting against the packing member 134 by means of an elastic force of a spring 138.
In the conventional ink cartridge shown and FIG. 28, the packing member 134 serves as a valve seat sealing the ink supply port 132 with the connecting means, and the ball 136 serves as a valve body closing the ink supply port 132 in cooperation with the packing member 134. However, the relative position between the ball 136 and the spring 138 is unstable. This may cause an undesirable insufficient sealing by the ball 136 with the packing member 134. Furthermore, the connecting means needs to have a large contact area to sufficiently urge the ball 136 against the elastic force of the spring. Therefore, the connecting means is not easily inserted in the packing member 134. Furthermore, because the ball 136 is always urged toward the packing member 134 by the spring, the through hole of the packing member 134 may be expanded. This is disadvantageous because it may cause an insufficient connection between the ball 136 and the packing member 134.
The present invention was made in view of the foregoing problems or drawbacks accompanying the conventional sealing structure of the conventional ink cartridge. Therefore, it is an object of the present invention to provide an ink cartridge and an ink supply system for an ink jet type printing apparatus capable of closing an ink supply channel assuredly, sufficiently when it is not mounted on the printing apparatus and capable of opening the ink supply channel to allow ink to smoothly flow to a print head when it is mounted on the printing apparatus.
Another object of the present invention is to provide an ink-jet type printing apparatus employing such ink cartridge.
The above and other objects can be achieved by combinations of the features recited in independent claims of the present application. Dependent claims define further advantages and exemplary combinations of the present invention.
In order to solve the above-stated problems and drawbacks accompanying the conventional ink cartridges, the present invention provides an ink cartridge for a printing apparatus providing ink to a print head through a tapered ink supply needle and removably attached to the print head, including: an ink chamber for containing ink; an ink supply port for supplying ink from the ink chamber to the print head of the printing apparatus, the ink supply port including an external opening; a packing member provided in the ink supply port, forming an ink channel for allowing a flow of ink, the packing member sealing the ink supply needle of the printing apparatus by fitting therewith; and a valve device contained in the ink supply port elastically abutting against the packing member, the valve device selectively opening and closing the ink channel in conjunction with the ink supply needle.
In order to solve the above-stated problems and drawbacks accompanying the conventional ink cartridges, the present invention further provides an ink cartridge for a printing apparatus providing ink to a print head through an ink supply needle and removably attached to the print head, including: an ink chamber for containing ink; an ink supply port for supplying ink from the ink chamber to the print head of the printing apparatus, the ink supply port including an external opening; a packing member provided in the ink supply port, forming an ink channel for allowing a flow of ink, the packing member sealing the ink supply needle of the printing apparatus by fitting therewith; and a valve device contained in the ink supply port elastically abutting against the packing member, the valve device selectively opening and closing the ink channel in conjunction with the ink supply needle, the valve device being urged by the ink supply needle of the printing apparatus to open the ink channel at a same time when the ink supply needle is sealed by the packing member.
The valve device may come to close the ink channel of the packing member before the ink supply needle of the printing apparatus is completely detached from the packing member.
In order to solve the above-stated problems and drawbacks accompanying the conventional ink cartridges, the present invention further provides an ink cartridge for a printing apparatus providing ink to a print head through an ink supply needle and removably attached to the print head, including: an ink chamber for containing ink; a porous member accommodated in the ink chamber for absorbing ink; an ink supply port for supplying ink from the ink chamber to the print head of the printing apparatus, the ink supply port including an external opening; a packing member provided in the ink supply port, forming an ink channel for allowing a flow of ink, the packing member sealing the ink supply needle of the printing apparatus by fitting therewith; and a valve device contained in the ink supply port elastically abutting against the packing member, the valve device selectively opening and closing the ink channel in conjunction with the ink supply needle.
In order to solve the above-stated problems and drawbacks accompanying the conventional ink cartridges, the present invention further provides an ink cartridge for a printing apparatus providing ink to a print head through an ink supply needle and removably attached to the print head, including: an ink chamber for containing ink; an ink supply port for supplying ink from the ink chamber to the print head of the printing apparatus, the ink supply port including an external opening; a packing member provided in the ink supply port, forming an ink channel for allowing a flow of ink, the packing member sealing the ink supply needle of the printing apparatus by fitting therewith, the packing member including a hole and a protruding rim surrounding the hole; and a valve device contained in the ink supply port elastically abutting against the packing member, the valve device selectively opening and closing the ink channel in conjunction with the ink supply needle, the valve device including a substantially flat surface at least at a part with which the ink supply needle contacts.
The packing member may include a first surface facing the ink chamber formed with a cylindrical recess having a diameter acceptable to receive a part of the valve device at the first surface.
The hole of the packing member may have a diameter smaller than the diameter of the cylindrical recess at the first surface.
In order to solve the above-stated problems and drawbacks accompanying the conventional ink cartridges, the present invention further provides an ink cartridge for a printing apparatus providing ink to a print head through an ink supply needle and removably attached to the print head, including: an ink chamber for containing ink; an ink supply port for supplying ink from the ink chamber to the print head of the printing apparatus, the ink supply port including an external opening; a packing member provided in the ink supply port, forming an ink channel for allowing a flow of ink, the packing member sealing the ink supply needle of the printing apparatus by fitting therewith; and a valve device contained in the ink supply port elastically abutting against the packing member, the valve device selectively opening and closing the ink channel in conjunction with the ink supply needle, the valve device including a valve body contacting with the packing member and including a substantially flat surface with which the ink supply needle contacts.
In order to solve the above-stated problems and drawbacks accompanying the conventional ink cartridges, the present invention further provides an ink cartridge for a printing apparatus providing ink to a print head through an ink supply needle and removably attached to the print head, including: an ink chamber for containing ink; an ink supply port for supplying ink from the ink chamber to the print head of the printing apparatus, the ink supply port including an external opening; a packing member provided in the ink supply port, forming an ink channel for allowing a flow of ink, the packing member sealing the ink supply needle of the printing apparatus by fitting therewith; and a valve device contained in the ink supply port elastically abutting against the packing member, the valve device selectively opening and closing the ink channel in conjunction with the ink supply needle, the valve device including: a valve body contacting with the packing member and urged by the ink supply needle of the printing apparatus to open the ink channel when the ink cartridge is mounted on the printing apparatus; and a guide body for guiding the valve body to slide substantially vertically with respect to the packing member.
The valve device may include: a valve member selectively contacting with a surface of the packing member, the valve member being forced by the ink supply needle of the printing apparatus when the ink cartridge is mounted on the printing apparatus; and an elastic member always urging the valve member toward the packing member.
The valve member may include a support structure for supporting the elastic member. The support structure may be radially shaped. The valve member may include a flange for supporting the elastic member.
The packing member may also include a second surface facing the external opening with a tapered portion tapered from the external opening toward the ink chamber at the second surface, for guiding the ink supply needle of the printing apparatus. The tapered portion may fit with the ink supply needle.
The packing member may include a second surface facing the external opening with a fitting portion to fit with the ink supply needle of the printing apparatus.
The packing member may be made of an elastic material and provided with a lubricant coat at least at an area with which the ink supply needle contacts.
The valve device may include a substantially flat surface with which the ink supply needle contacts.
The valve body may include: a sealing portion for closing the ink channel of the packing member when the valve body contacts with the packing member; and an ink channel allowing ink to pass therethrough when the valve body is urged to come out of contact with the packing member by the ink supply needle of the printing apparatus.
At least a part of the ink channel of the valve body may be formed by cutting off the sealing portion.
The sealing portion of the valve body may include a substantially flat surface with which the ink supply needle contacts.
The guide body may include: an axial portion being connected to the valve body; and a guide block formed at an end of the axial portion opposite to the valve body, the guide block guiding the valve body to slide substantially vertically with respect to the packing member.
The axial portion of the guide body may be formed as one unit with the valve body.
The ink cartridge may further include a guide unit provided in the ink supply port to receive the guide block of the guide body.
The valve body and the guide body may be separately formed and fixed to each other by fixing means.
The guide body may be made of an elastic material. The guide body may be formed with a groove extending from the guide block through the axial portion.
The valve body of the valve device may include a surface facing the packing member formed with a convex surface.
The valve body of the valve device may include a surface, facing the packing member, formed with a protruding portion to contact with a tip end of the ink supply needle.
The valve body of the valve device may include a surface, facing the packing member, provided with a notch.
The notch of the valve body may have a tapered angle which is the same as that of the tapered ink supply needle.
The channel of the valve body may have a tapered angle which is smaller than that of the tapered ink supply needle.
The valve body of the valve device may include a surface, facing the packing member, formed with a spherical surface contacting with a tip end of the ink supply needle.
The spherical surface of the valve device may have a diameter of curvature larger than a diameter of a widest part of the valve body.
The packing member may include a first surface facing the ink chamber with a protruding portion having a hole whose diameter is smaller than the diameter of the ink supply needle of the printing apparatus.
The packing member may include a first surface facing the ink chamber with a protruding portion having a hole whose diameter is smaller than the diameter of the ink supply needle of the printing apparatus.
The spherical surface of the valve device may be formed with a flat portion at its center having a smaller diameter than a diameter of the hole of the protruding portion of the packing member.
The valve device may include: a valve body contacting with the packing member and urged by the ink supply needle of the printing apparatus to open the ink channel when the ink cartridge is mounted on the printing apparatus; and an elastic support portion for supporting the valve body.
The ink cartridge may further include a packing retainer for retaining the packing member at the external opening of the ink supply port.
The packing retainer may include a film capable of being penetrated by the ink supply needle of the printing apparatus.
The film may be formed with a hole which enables the ink supply needle to easily pass through.
The hole may be formed by cutting the film in a cross shape.
The packing retainer may be a protruding portion protruding from the external opening toward the center thereof.
The ink supply port may have an internal opening open to the ink chamber, and the ink cartridge further includes a filter provided at the internal opening.
The fitting portion may include a first fitting position for fitting the ink supply needle of the printing apparatus when the ink supply needle is inserted from the external opening, and a second fitting position for fitting the ink supply needle when the ink supply needle is further inserted toward the ink chamber.
The first fitting position may be initially sealed prior to use.
According to another aspect of the present invention, in the above-stated problems and drawbacks can be solved by a provision of an ink supply system for an ink-jet type printing apparatus supplying ink contained in an ink cartridge to a print head through a tapered ink supply needle, the ink supplying system including: an ink channel for providing ink from the ink chamber to the print head of the printing apparatus; a first member provided at the ink channel, forming a part of the ink channel for allowing a flow of ink, the first member sealing the ink supply needle of the ink printing apparatus by fitting therewith; and a second member contained in the ink channel elastically abutting against the first member, the second member selectively opening and closing the ink channel in conjunction with the ink supply needle.
According to still another aspect of the present invention, the above-stated problems and drawbacks can be solved by a provision of a printing apparatus for ejecting ink on a printing medium, which includes: a print head; a tapered ink supply needle; and an ink cartridge communicating with the print head through the tapered ink supply needle and removably attached to the print head. The ink cartridge includes: an ink chamber for containing ink; an ink supply port for supplying ink from the ink chamber to the print head of the printing apparatus, the ink supply port comprising an external opening; a packing member provided in the ink supply port, forming an ink channel for allowing a flow of ink, the packing member sealing the ink supply needle of the printing apparatus by fitting therewith; and a valve device contained in the ink supply port elastically abutting against the packing member, the valve device selectively opening and closing the ink channel in conjunction with the ink supply needle.